Compass



April 22, 1924. 1,491,593

E. B. ERIKSEN COMPASS Filed Sept. 24. 1919 2 Sheens-Sneet 1 (qu aufm. MKM

pril 22 1924. 1,491,593 E. B. ERIKSEN COMPASS Fild Sent. 24. 1919 2 Sheets-Sheet 2 Plasma Apr. 22, 1924.

UNITE-o STATES EINAR B. ERIXSEN, OF BROOKLYN, NEW YORK, ASSIGNOB T0 ERNEST W. HALL,

or YoNxEns, Naw Yoan.

cosa-Miss f Application mea september' 24, ibis. semi4 No. 326,007.

To all whom z't may concern.' y

Be it known that I, EINAR B. ERIKSEN, a citizen of the United States, and a resident of Brooklyn, county of Kings, and State of.

New York, have invented certain new and useful Im rovements in Compasses, of which the. ollowing is a specification, reference being had to the accompanying drawings," forming a part thereof.

My present inventionrelates particularly to Compasses of the nautical type and the objects of the invention are to simplify and improve the construction particularly as regards the compensating mechanism and the.

structure of the magnetic element.

A special feature of the inventlon 1s a compensating mechanism in the form of a substantially flat diaphragm sealed over' a compensating pocket or chamber in the bowl of the compass and flexible to opposite sides of the general flat plane of the diaphragm. The magnetic element is pivoted independently of this diaphragm on a base which may be secured to the compass bowl at the same point where the diaphragm is secured thereto.

This magnetic element comprises in the preferred construction a hollow casing presenting smooth friction reducing surfaces to the liquid within the bowl and containing a series of magnet bars secured in substantially parallel spaced relation. v

Other features of the invention will appear as the specification proceeds.

In the accompanying drawings I have illustrated a practical and preferred embodiment of the invention, but would have it understood that modifications may be made without departure from the true spirit and scope of the invention as defined in the appended claims.

In these drawings, Figure 1 is a vertical sectional view through the central portion of the compass.

Figure 2 is a plan view of the compass.

Figure 3 is a detail sectional view, illustratin the separated portions of the magnetic e ement.

Figure 4 is a plan view of the magnet assemb y.

Figure 5 is an edge or bell section of th magnet assembly as looking towards the right-hand side of Figure 4.

Like characters refer to corresponding parts throughout the several views.

`shape overstan designates a box or housing for the bowl @of a compass which in accordance with my invention is preferably constructed in asingle piece,- for instance, of'spun brass and o rmcd with an integral pocket or depression 7 in thebottom thereof to provide a holder for the lead or weight material 8 and a socalled compensating chamber. At the upper rim portion I have shown this bowl reinforced with a heavy annular section 9, which may be of cast metal and to which may be secured the annulus 10, which seals the cover plate 11 in position. A simple .method of securing these parts is to provide' Athe spun portion of the bowl with an annularly e corrugated, as indicated, to render it l more flexible. This diaphragm is secured over the compensating pocket in any suitable way, for instance, by having its rim soldered to the bottom of the bowl, as indicated at 1 The magnetic element is mounted on a pivot ost 16 which is carried in this instance y base (plate 17 of generally arched ing the diaphragm and secured in place by having its 'rim portion secured over the rim portion of the diaphragm, as indicated at 18. In ractice the diaphragm may have its edge anged and turned over the edge of the base ,plate 17, as shown. By means of this arrangement both the base for the pivot post and the diaphragm may be secured in place by a single soldering operation.

The bowl above the diaphragm contains a -suitable li uid for giving iotation to the magnetic e ement or compass card, as will be readily understood and the pivot post base is perforated or provided with openings as at 19 to admit the liquid to the diasov ino'

the bowl, the body of air or gas below the diaphragm acting to cushion such movements of the diaphragm. v

The magnetic element consists in the present preferred construction of a plu rality of magnet bars of graduated length arranged in spaced arallel relation within a float or casing of isk shape and made up of upper and lower disk members 21 and '22, connected at their edges by the overlapping flanges 23 and 24. The lower disk member is furthermore shown as carrying a central tubular projection or thimble 25 of substantially conical shape. The upper disk member serves as a cover and is shown provided with a dome-shaped central portion 26 preferably arranged to meet the top of the tubular projection 25. Within the upper end of the tubular portion is a bearing which coacts with the first post to support the magnetic element. -This bearing is shown as a jewel 27, held in place by an adjustable screw 28 seated in the screw threaded upperend of the tubular connecting member 25.

The thimble or projection 25 is shown as a separate conically shaped element having its base secured to the under portion of the lower disk 22 and its upper end secured to the dome 264 of the upper disk. The com.

pass card or dial 29 is .provided with a central opening to permit the entry of the dome 26 and is supported in close proximity to the glass cover by means of brackets 33 rising from the float. These brackets are of sufficient height to su port the dial in line with the pivot on which the float is balanced. This arrangement of the compass card is an impertant feature of my invention.

The magnet bars 20 are secured in the casing in parallel spaced relation, according to the present disclosure, by means of channel strips 30, said strips being disposed in parallel relation within the casing and having registering openings 31 in the backs or bottoms of the channels l:to receive the magnet bars. Vhen the bars are passed through these openings, the top and bottom flanges of the strips, which are disposed on edge, overlie the upper and lower edges of the magnet bars so that the whole forms a grid, as indicated in Figure 4, in which the bars and strips memes respectively stand in substantially parallel relation. i

The construction disclosed provides a magnet assembly having strong magnetic properties and this element swings freely within the compass bowl by reason of the fact that the magnet bars are all 'encased within a cover which presents a smooth and unobstructed surface to the compass liquid. The compass movements therefore are not retarded and the action of the parts is substantially frictionless, this partly due also to the floating effect of the casingwhich takes a good deal of the weight off the pivot post.

l/Vhat I claim is:

l. Ina compass, the combination with the bowl thereof, of a stepped ring surrounding the rim of the bowl, a flange projecting laterally from the bowl rim and seated on the step, a transparent cover seated on the ange, and means providing a seal between the liange and cover.

2. A magnetic element for Compasses comprising a disk member having an upstanding flange at the rim thereof and an upstanding tubular projection at the center thereof, a second disk member having a dependent annular flange for engagement with the ange of the lirst disk member and a dome-shaped central portion for engagement with the tubular projection of the first member, a pivot bearing seated in the tubular projection and one or more vmagnet Abars secured between the two disk members.

3. A compass comprising a bowl provided with a compensating pocket,a base plate, a flexible diaphragm covering the compensating pocket and having its rim portion flanged over the edge of the base plate, said fiange portion of the diaphragm being secured by solder or the like to the bowl to thereby seal the diaphragm over the compensating pocket and secure the base plate in fixed position, a post carried by the base plate and a compass element supported on said post.

In witness whereof I `hereunto set my hand this 12th day of September, 1919.

EINAR B. ERIKSEN. 

